Wednesday, 17 May 2017

Latin binomials and the beauty of common names

I first became fascinated by
larval blackflies as an undergraduate: there was something about their
structure, means of attachment to substrata in fast-flowing streams and rivers,
and their ability to feed on particles carried by the current. I went on to
study the distribution of larvae in moorland streams for my PhD under the
inspiring supervision of Dr Lewis Davies at Durham and this led to my independent
investigations on larval feeding. I then became interested in the biology of
larvae inhabiting lake outlets after meeting Staffan Ulfstrand and the
Rheo-Group at the University of Lund in Sweden. We carried out field work in
Swedish Lapland and could only provide speculative answers as to why some
species are found in huge numbers where rivers drain from lakes.

Blackflies is one common name in
English for these insects and they are not to be confused with aphids that
inhabit legumes, although they share the same name. You will note that I have
also used one word, whereas in North America these insects are called Black
Flies - or Buffalo Gnats, a reference to the hunched appearance of the thorax
(see above). Having complete metamorphosis, the adults look very different to
the larvae and also to the pupae, but the term black fly or blackfly applies to
all three stages.

To overcome confusions in the use
of common names, both within and between languages, Linnaeus proposed the universal
adoption of the Latin binomial system of nomenclature, as in Homo sapiens, for example. This allows
accurate identification that is worldwide and international bodies administer
the rules of nomenclature [1,2] and act as final arbiters should there be disputes. Even after Latin binomial names
become established, they can be changed. After my Swedish adventure, I began
studying lake outlets in England, where one species of blackfly, named Simulium argyreatum (it doesn't have a
common name to my knowledge), is found in such huge densities that
larval masses look like the thick pile of carpets. A few years after I started looking at the
biology of this fascinating animal, its name was changed to Simulium noelleri. This was after a
careful examination of species described by an entomologist named Meigen, and
following the rules of nomenclature [3] (if you would like to read more about nomenclature
of these insects, or any other aspect of their biology, you should read Roger
Crosskey's brilliant book The Natural
History of Blackflies, see below).

The revision meant that my publications
contain papers that use two different species names, yet they are the same
species, and I became so identified with the larvae of S. noelleri (ex. S.
argyreatum) that a cartoon was drawn of me as a larva of this species,
complete with head fans and mouthparts instead of hair (see below). Those who
chuckle at the humour are probably unaware of the name change.

The disadvantage of common names,
compared to Latin binomials, is that there is no overall authority to oversee
their use and there are a large number of names in many languages. However,
they are more easily remembered. Thus, anglers identify blue-winged
olives, but not Serratella ignita, and the common name applied to
the adults is also applied to larvae, even though they are yet to have wings.
Many who take part in the excellent programme of Riverfly monitoring [4], used
to assess the condition of rivers in the UK, use common names rather than
the Latin binomial, especially as not all Riverflies are identified to this
taxonomic level.

Common names are not only easier
to remember; they are also descriptive. For example, the fungus Amanita phalloides is better known as
the Death Cap and Amanitavivosa as the Detroying Angel – both are
highly poisonous to humans. Many other species of organisms have been given splendid,
almost poetic, names:

Hare's ear (fungus)

Dryad's saddle (fungus)

Death's head hawk moth (moth)

Dusky brocade (moth)

Sooty gossamer-wing (butterfly)

California dog-face (butterfly)

Jack-go-to-bed-at noon (wild flower)

Smooth hawk's beard (wild flower)

Pied wagtail (bird)

Chestnut-headed flufftail (bird)

This is but a small selection
from thousands of names that certainly stick in the memory of English speakers,
but they mean little to those who use different languages and that's the
problem that is solved by Latin binomials. There is richness in the common
names though, even those that are very local, and they lend themselves to what
Gosse described as the Romance of Natural History. I'm pleased that we continue
to use them.